Gas turbine power plant control apparatus having a multiple backup control system

ABSTRACT

A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

I United States Patent 11 1 1111 3,91 1,285 Yannone et a1. Oct. 7, 1975 [54] GAS TURBINE POWER PLANT CONTROL 3,469,395 9/1969 Spitsberger 60/39.28 APPARATUS HAVING A MULTIPLE 3,482,396 12/1969 Nelson et al..... 60/39.28 3,564,273 2/1971 Cockrell 290/40 BACKUP CONTROL SYSTEM 7 3,588,265 6/1971 Berry 60/105 [75] Inventors: Robert A, Yannone, Aldan; James J, 3,606,754 9/1971 White 60/39.28 Shield Phil d l hi b th f P 3,738,102 6/1973 Stearns 60/39.28

[73] Assignee: yestlinghlouie' Electric Corporation, Primary Examineflc R Simmons ms urg Attorney, Agent, or FirmS. A. Seinberg [22] Filed: June 20, 1973 Appl. No.: 37 1,625

US. Cl 290/40; 60/39.28 T; 322/14 [5 7] ABSTRACT A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbinegenerator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system [56] References Cited- A E S also contains monitoring and protective subsystems UNITED STATES T N which function through all stages of operation, with 3,340,883 9/1967 Peternel .1 290/40 redundancy and permissive features which maximize 3,382,671 5/l968 Ehni 60/39.28 turbine availability 3,382,672 5/1968 French..... 60/39.28 3,446,224 5/1969 Zwicky 60/39.28 24 Claims, 40 Drawing Figures 2c 2so PEAK PZC/ HPZC) SYS. RES- P BASE 251 s 203 EXHAUST (T EXH TEMR THERMOCOUPLES- f 2T) NT OL Tz P 1 LOAD) 267 2 P zc/ I gl ART AMBIENT CONTROL TEMP B/P TEMP. SlfZrNSORS 253 CONTROL T231 /P (STARTING a TRANSIENT) /25B J BLADE PATH f THERMOCOUPLES (TZT) .iAccEL.

TZT/ P 204 51811111. SPEED SELECT (LSSl zc TOTAL LOAD (B/V) RATE SPEED SPEED LOAD 23' CHANGER CONTROLLER zos SPEED SENSOR ss-m 65L LOAD I FAST CHANGER NORMAL I88 LOAD RATE mm '5 L53 OUTPUT U.S. Patent Oct. 7,1975 Sheet20f'26 3,911,285

U.S. Patent Oct. 7,1975

Sheet 3 of 26 3,911,285

IGNITION SYSTEM Fig, 3

T08 F lg. [48 1 HOUR TIMER MANUAL couNTER AT oNE T 1 REsET N E sHuTDowN COUNTER CONDITIONS OR A couNTER AT zERo MASTER I lcoNTRoL (4Y1) LOCKOUT SIGNAL MIN LSX TWO-SHOT o BASE OR A RESTART LIJ PEAK (REX) LU 0.. (I)

LOCKOUT NOT F. [40 SIGNAL q' F I4 C US. Patent 0a. 7,1975 She et5 of 26 3,911,285

Fzc 25o PEAK p f(P SYS- RES. P l BASE- I 25| S f/ 203 EXHAUST (T EXH TEMP. THERMOCOUPLES. f T $0813? L P v 267 52X 1 TOTAL o START AMBIENT CoNTRoL TEMP T B/P TEMP. SENSORS CoNTRoL T23l 1C/ r/ 253 (STARTING a EXH 25 TRANSIENT) F BLADE PATH flT I THERMOCOUPLES 2T ACCEL LOW TZT/ P 204 SIGNAL SPEED LOADI SELECT (LS8) PZC LOAD oTAL (B/V) T RATE SPEED SPEED L0AD 23 CHANGER CoNTRoLLER T 205 SPEED ,L SENSOR 260 Gs-EN 65L LOAD FAST v CHANGER NORMAL l88 LoAD RATE --Lss OUTPUT TIg,5

SPEED LOAD U.S.- Patent Oct. 7,1975

MIN LOAD BKR.CL.OSE (100% SPEED) STARTING BLADE TEM PERATURE TEMPERATURE U.S. Patent IL Oct. 7,1975 Sheet 8 of 2 3,911,285

EXH

EXH

LOAD

I SPEED LOAD LSS I 229 ACCELI P6 I AR LOAD RATE BR LRL 4- LSS OUTPUT ACCEL. COMP. DISCH. UMIT TOTALIZER Fig 7A Pate-m mamas; SIee QIIZG 3911 2851 .|I Q U Eu RP US I FS A E w 6 W m T m I L R W SAN. GSS n u T J P W P C ,I R S C .7 G |IIIL 5 5 2/ 2 1 R m AL V V 4 q. P m m if I 2 6 RI\ R a E E SW I L LE AL IL GA on T O O T T C w a I C E 2 R 3 S P U 3 D1 s 2 H B R a R 5 P M R 2 P 3 P G 2 I R OA BR Lmw E P S US 6 F D B REG- VALVE TO COMBUSTION S STEM ;TO COMBUSTION SYSTEM UEL OIL OIL T a T.V. I I I I I I LTRANSFER I SWITCH J PRESSURE REG. VALVE GAS GAS FUEL GAs STARTING SIGNAL U.S. Patent Oct. 7,1975 Sheet 10 Of26 4 3,911,285

FLMl L 6 FLM1 I "FLMZ \274 2 I25 VDC I 744 FLM1 T 275 276 1 2725 272 FLMX 273 274 F lg. 86

3% FROM FUEL OIL PUMP cOMBusTOR L- TO STORAGE POP} 5 I09 I R .0 30 LU '1 NOzzI E PRESSURE I RUN POSITION 1 41- CE 7 A I f; D 9 GLIDE =ffi/ hi I I E R1 SPEED) (1.7.-- O x I P-T POSITION 2 15------7 I I l PRE- I I FIRE POSITION 20% ISOLATION FLAME ENOv SP ED OPEN GLIDE TIII/IE-+ I US. Patent Oct. 7,1975 Sheet 14 of 26 Timwm Twziwmol Twwmwml oz 

1. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator driven by said gas turbine, a fuel system for supplying fuel to said gas turbine combustion element, a control system having a plurality of control paths with inputs constantly connected to predetermined elements of said turbine and said generator, the output of said control system being connected to and continuously providing an output signal for operating said fuel system to energize said turbine, said control paths including a first plurality of primary control paths for developing a primary control signal for operating said fuel system during turbine startup, load and shutdown operations, and a second plurality of control paths for developing temperature backup control signals, each said backup control signal being a predetermined function of the temperature of a respective one of said turbine elements and at least one other turbine operating condition, said control system including means for selecting one of said backup signals as said control system output under predetermined turbine conditions.
 2. The gas turbine electric power plant as set forth in claim 1 wherein said plant comprises a plurality of controlled auxiliary devices associated with startup, run and shutdown operations of said gas turbine and said generator, a plurality of process sensors disposed to detect predetermined plant conditions related to said turbine and said generator and to provide inputs to said control paths, said control system operating to sequence said controlled auxiliary devices for turbine plant startup, run and shutdown operations in response to the conditions monitored by said sensors.
 3. The gas turbine electric power plant as set forth in claim 2, wherein a first of said temperature backup control paths is adapted to maintain a substantially constant steady state generator output, while another of said temperature control paths is a backup to said first temperature control path and is adapted to control against transient temperature excursions in said turbine.
 4. The gas turbine electric power plant as set forth in claim 3, wherein said control system determines a fuel demand representation for desired turbine operation, and said fuel system is controlled and operated in accordance with said fuel demand representation.
 5. The gas turbine electric power plant as set forth in claim 1, wherein each of said control paths contains an input sensor, a transducer, and a control function generator portion, and each said control function generator portion is pneumatic.
 6. The gas turbine electric power plant as set forth in claim 1, wherein said control paths include a speed control path for control of turbine startup, a load control path for control of turbine load, a rate control path for limiting the rate of load increase, and at least two temperature backup control paths, and said selecting means is adapted to select the lowest signal generated by said control pathS.
 7. The gas turbine electric power plant as set forth in claim 6, wherein each said control path contains means for generating a pneumatic signal, and said selecting means is a low pressure select element.
 8. The gas turbine electric power plant as set forth in claim 7, wherein said fuel system contains pneumatic means for operating said system so as to control said supply of fuel, and the output of said selecting means is directly connected to said operating means.
 9. The gas turbine electric power plant as set forth in claim 8, wherein one of said temperature backup control paths has means for developing a signal which is a function of blade path temperature and of a setpoint derived from compressor discharge pressure and ambient temperature.
 10. The gas turbine electric power plant as set forth in claim 9, wherein one of said backup control paths has means for developing a signal which is a function of turbine exhaust temperature and of a setpoint derived from compressor discharge pressure.
 11. The gas turbine electric power plant as set forth in claim 6, wherein said speed control path contains a plurality of input subpaths, and means for selecting the highest signal from said subpath.
 12. The gas turbine electric power plant as set forth in claim 11, wherein said speed path contains two such subpaths, and means for determining the difference between the input signals of said subpaths.
 13. The gas turbine electric power plant as set forth in claim 6, wherein each of said temperature backup control paths contains a plurality of input subpaths and means for selecting the highest signal from said subpaths.
 14. The gas turbine electric power plant as set forth in claim 13, wherein a first of said temperature backup control paths contains means for operating on said selected input signal so as to enhance its response to changes with time, said path including means for providing setpoint input which is a function of the desired level of turbine load.
 15. The gas turbine electic power plant as set forth in claim 14, wherein a second of said backup control paths contains means for biasing its output signal to be normally relatively greater than that of said first backup path.
 16. The gas turbine electric power plant as set forth in claim 15, wherein said second backup control path has a faster time response than said first backup control path.
 17. The gas turbine electric power plant as set forth in claim 1, wherein each of said control paths generates a control signal, and said control system contains means for selecting the lowest signal generated by said control paths and providing same as said control system output, and means for displaying which control path signal is said selected lowest signal.
 18. The gas turbine electric power plant as set forth in claim 9, wherein said blade path backup control path contains a pneumatic controller which produces an output signal which is proportional and integral.
 19. The gas turbine electric power plant as set forth in claim 1, wherein each of a plurality of said control paths contains a sensor for providing an input signal representative of a turbine condition at one of said predetermined turbine elements and means for generating a control signal as a function of said sensed input, said input signals being electrical and said electrical control signal being pneumatic, and means for transducing in each of said respective control paths from an electrical signal to a pneumatic signal.
 20. The gas turbine electric power plant as set forth in claim 19, wherein one of said paths is a speed control path for controlling the speed of said turbine during turbine startup, said speed control path containing a pneumatic speed function generator.
 21. The gas turbine electric power plant as set forth in claim 6, said load control path containing a pneumatic load generator for generating a load signal for controlling increase in turbine load.
 22. A gas turbine electric power plant comprisiNg: a. a gas turbine, having compressor, combustion and turbine elements; b. a generator coupled to said gas turbine for drive power; c. a generator breaker for coupling the generator to a power system; d. a fuel system for supplying fuel to said gas turbine combustion element; e. a control system having a plurality of control paths, each of which generates a respective control signal, and including at least two control paths which generate respective temperature backup control signals which are functions of the temperature at respective different portions of said gas turbine; f. a first of said temperature control paths providing a relatively fast response and a second of said temperature control paths providing a relatively slower response to its respective turbine temperature condition; g. each of said temperature control paths containing means for generating setpoint signals, said at least two control paths having respective generated setpoint signals which are independent during a first phase of said turbine operation and common during a second phase of said turbine operation; h. means for selecting one of said control signals and operating said fuel system in response thereto; i. a plurality of controlled auxiliary devices associated with startup, run and shutdown operations of said gas turbine and said generator; and j. a plurality of process sensors disposed to detect predetermined plant conditions related to said turbine and said generator to provide inputs to said control paths, said control system operating to sequence said controlled auxiliary devices for turbine plant startup, run and shutdown operations in response to the conditions monitored by said sensors.
 23. The gas turbine electric power plant as set forth in claim 22, wherein a first of said temperature backup control paths is adapted to maintain a substantially constant steady state generator output, while another of said temperature control paths is a backup to said first temperature control path and is adapted to control against transient temperature excursions in said turbine.
 24. The gas turbine electric power plant as set forth in claim 23, wherein said control system determines a fuel demand representative for desired turbine operation, and said fuel system is controlled and operated in accordance with said fuel demand representation. 